Name

       pnmtoddif - Convert a portable anymap to DDIF format

Syntax

       pnmtoddif pnmtoddif [-resolution x y] [pnmfile [ddiffile]]

OPTIONS

       resolution x y The  horizontal  and  vertical  resolution  of the output image in dots per
                      inch. Defaults to 78 dpi.

       pnmfile        The filename for the image  file  in  pnm  format.   If  this  argument  is
                      omitted, input is read from stdin.

       ddiffile       The  filename  for  the  image  file to be created in DDIF format.  If this
                      argument is omitted, the ddiffile is written to  standard  output.  It  can
                      only specified if a pnmfile is also specified.

DESCRIPTION

       pnmtoddif  takes  a  portable anymap from standard input and converts it into a DDIF image
       file on standard output or the specified DDIF file.

       pbm format (bitmap) data is written as 1 bit DDIF, pgm format data (greyscale)  as  8  bit
       greyscale  DDIF,  and  ppm  format data is written as 8,8,8 bit color DDIF. All DDIF image
       files are written as uncompressed. The data plane organization is interleaved by pixel.

       In addition to the number of pixels in the width and height dimension,  DDIF  images  also
       carry  information  about the size that the image should have, that is, the physical space
       that a pixel occupies. PBMPLUS images do not carry this information, hence it  has  to  be
       externally  supplied.   The default of 78 dpi has the beneficial property of not causing a
       resize on most Digital Equipment Corporation color monitors.

AUTHOR

       Burkhard Neidecker-Lutz
       Digital Equipment Corporation, CEC Karlsruhe
       neideck@nestvx.enet.dec.com

                                                                                     pnmtoddif(1)